Bald eagles soaring to recovery in Bay Area and state

Environmentalists held their breaths and watched as a feathery brown eaglet leapt from its nest for the first time -- a very real sign of the comeback of the bald eagle in the Bay Area and the nation.

National symbol or not, the eaglet soared and then landed awkwardly on the ground as its human monitors first rejoiced and then gasped with fear at seeing the new flier exposed to earthly dangers.

The bald eaglet -- the first to hatch near Lake Chabot in Castro Valley in modern times -- was playing its part Friday in a mini-drama in the recovery of a species that nearly vanished.

"The bald eagles are coming back," said Doug Bell, a wildlife biologist with the East Bay Regional Park District. "Sometimes I have to pinch myself. About 1965, when I become interested in raptors, there were no eagle nests in the Bay Area."

The newly fledged eagle expanded the small but growing number of successful Bay Area bald eagle nests, helping fuel the bird's nationwide recovery.

The iconic bird known for its fierce gaze, strength and wild spirit had been nearly wiped out in the lower 48 states by the early 1960s. Development had damaged its habitat; DDT, a pesticide since banned, made the bird's egg shells too weak for hatching.

Nests popping up

In the Bay Area in the past decade or so, however, pairs of the fish-eating raptors nested at several sites.

They include San Pablo Reservoir near Orinda, Del Valle Reservoir near Livermore, Calaveras Reservoir on the edge of Santa Clara and Alameda counties, San Antonio Reservoir south of Sunol, Lake Berryessa in Napa County, and Lake Sonoma in Sonoma County, according to the state Department of Fish and Game.

In addition to the new nest at Lake Chabot this year, bald eagles produced young for the first time at the Sacramento National Wildlife Refuge.

In the spring, bald eagle pairs made failed attempts to build the first nests in at least many decades in San Mateo and Santa Cruz counties -- at Crystal Springs Reservoir and at Pinto Reservoir near Watsonville.

Experts said the attempt was progress, as eagle pairs often strike out at a nest site for one or two years before producing young.

"What we've got is a situation where there are quite a few eagles and they are starting to encounter one another and think about breeding," said Glenn Stewart, director of the Santa Cruz Predatory Bird Research Group. "They'll be back next year, back and more experienced."

The eagle's recovery has been aided by pesticide restrictions, habitat protections and the release of captive-bred chicks.

State and federal agencies don't have a concrete estimate for nesting pairs in California; tracking and study funds have shrunk since the birds were removed from the federal endangered species list in 2007. But anecdotal evidence suggests numbers have grown since 2007, when there were more than an estimated 200 nests, said Cari Battistone, a state Fish and Game scientist.

In 1963, there were only 417 known nests in the lower 48 states, a fraction of the more than 10,000 nests now, federal wildlife officials estimate. Alaska, with its vast open lands and rivers and fewer humans, has 50,000 to 70,000 eagles.

"Bald eagles used to be extremely rare to see," said Maury Stern, a Lafayette birder for nearly 40 years. "Now, it's becoming more common. It's still a thrill, though, to see them soaring in the air."

Weighing 10 to 14 pounds with wingspans from 72 to 90 inches, adult bald eagles are third to condors and golden eagles as the biggest birds in American skies.

Bay Area birders in recent years have begun to see bald eagles outside the winter months -- the time when migrants fly through the region. The reason is some eagles are making the Bay Area their home rather than just passing through.

Though more than 7 million people live in the Bay Area, the region still has what bald eagles want: open space, big trees to support nests, and water reservoirs to fish in.

The first bald eagles to nest in Contra Costa County in modern times chose a site in 2006 east of the San Pablo Reservoir near Orinda. The nest has produced two or three eaglets a year since then -- including last spring.

A perfect home

"We have the perfect situation for them with reservoirs surrounded by protected watershed," said Jim Smith, a biologist for the East Bay Municipal Utility District. "We leave them alone."

Smith and other biologists say they believe the big birds will find other nest sites to colonize in the Bay Area.

The future of bald eagles is not without obstacles, though.

Biologists say they face numerous threats: electrocution on power poles or lines; poisoning by pesticides; wind turbine accidents; automobile strikes; poisoning by lead bullet fragments in the animals they scavenge; and human harassment.

At Lake Chabot in the spring, bird watchers and monitors were excited to see the new eaglet eating fish dropped by its parents. The young bird snapped its beak so violently at food that the birds dropped fish into its mouth from a safe distance.

"We were concerned at first that this pair is so young that they might not have been ready to produce offspring," said Bell, the park district biologist. "We were skeptical, but they pulled it off."